Ripple Down Rule learner (RIDOR) is also a direct classification method. It constructs the default rule.
An incremental reduced error pruning is used to find exceptions with the smallest error rate, finding the best
exceptions for each exception, and iterating. The most excellent exceptions are created by each exceptions
produces the tree-like expansion of exceptions. The exceptions are a set of rules that predict classes other than
the default. IREP is used to create exceptions